Meggie's right. Tie your Anubias to a rock OR leave it to float. It makes a great Betta hammock. It thrives in any water and any light except very bright. Comes in small, medium, large and long-leaf. Doesn't grow very fast, so it's not a big ammonia eater. But you never have to trim it.

Can you tell it's my favorite plant?

I like Wisteria a lot, too, for many of the same reasons. Likes to float and makes great topcover, a feature that is not used often enough among the tanks I've seen. Also a good hammock.

I've had two double-divided tanks (with the filter and heater in the middle). Best way to go for a lot of reasons, imo.

Regardless of the wattage, a color temperature of 6500K is best for plants. It should say that on the package.

As for the sand, that's what I have in all of my tanks and they are all planted and doing just fine

For the anubias, you can't burry the rhizome (the thick stem part where all the leaves sprout from) you could burry just the roots and not the rhizome, but the best way (and the best looking way) in my opinion is to tie it onto a rock or piece of wood...I just use fishing line for mine

Has anyone ever divided a tank and used an undergravel filter?? I'm thinking that might work best.

You're welcome.

Imo undergravel filters have more minuses than pluses.
---You have to use a largish gravel that won't fall into/through the grate.
---It's hard to siphon old food and poop, so they're hard to keep clean.
---If you're cycling your tank they don't offer much area for the beneficial bacteria.
---They use a noisy airpump like a sponge filter.
---Yesterday's technology, invented just for appearance, not much used around here.

You're better off with a sponge filter or internal filter that you can put between your dividers. That is the idea behind a double-divided tank.